Before you go hire a business coach or sales person, enrol in an online course, follow a get rich quick scheme, do this first. Warning, this is a long list of things to do. No easy answers, no quick fixes, but the bare minimum of what you need to do before looking for more help. Remember, people hire who they know, who they like and who they trust. So time to get known.
Proof of concept in software development is a controversial topic. The person that came up with a software idea is usually convinced of its relevance. And stakeholders usually don't want to spend time on something that is not even going to be included in the final product.
Startups, Biz Dev
Proof of Concept in Software Development
Knowledge
Why Web Accessibility Is Important and How You Can Accomplish It